1. Field of the Invention
The present invention relates to a method for image processing, and more particularly, to a method for reducing impulse noise and the apparatus thereof.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a block diagram of a conventional impulse noise filtering device. The impulse noise filtering circuit 110 receives an image signal S_IN, which includes a plurality of image frames. The impulse noise filtering circuit 110 determines a specific image frame by utilizing a window. If the luminance of a certain pixel of the window is bigger (or less) than the luminance of other pixels of the window, the impulse noise filtering circuit 110 will record the location of the biggest (or least) pixel and records the luminance value of the biggest (or least) pixel. Then the impulse noise filtering circuit 110 further determines the pixel with sub-biggest (or sub-least) luminance and records the luminance value of the sub-biggest (or sub-least) pixel, then utilizes the luminance value of the sub-biggest (or sub-least) pixel to replace the original luminance value of the biggest (or least) pixel. However, the related art reducing impulse noise method is too simple and not able to correctly determine if the pixel having the biggest (or the least) luminance is impulse noise. Moreover, the method for utilizing the luminance value of the sub-biggest (or sub-least) pixel to replace the original luminance value of the biggest (or least) pixel will cause decrease the image quality. The drawbacks and limitations of the conventional methods regarding said luminance are well known to those having average skill in this art and therefore further details are omitted for the sake of brevity.
It is apparent that new methods and devices are required.